Metabolic engineering has been widely used for production of natural medicinal molecules. However, engineering high-yield platforms is hindered in large part by limited knowledge of complex regulatory machinery of metabolic network. N⁶-Methyladenosine (m⁶A) modification of RNA plays critical roles in regulation of gene expression. Herein, we identify 1470 putatively m⁶A peaks within 1151 genes from the haploid Saccharomyces cerevisiae strain. Among them, the transcript levels of 94 genes falling into the pathways which are frequently optimized for chemical production, are remarkably altered upon overexpression of IME4 (the yeast m⁶A methyltransferase). In particular, IME4 overexpression elevates the mRNA levels of the methylated genes in the glycolysis, acetyl-CoA synthesis and shikimate/aromatic amino acid synthesis modules. Furthermore, ACS1 and ADH2, two key genes responsible for acetyl-CoA synthesis, are induced by IME4 overexpression in a transcription factor-mediated manner. Finally, we show IME4 overexpression can significantly increase the titers of isoprenoids and aromatic compounds. Manipulation of m⁶A therefore adds a new layer of metabolic regulatory machinery and may be broadly used in bioproduction of various medicinal molecules of terpenoid and phenol classes.

Objective:In order to explore the impact of corona virus disease 2019(COVID-19)on the hospitalization of children with bronchiolitis and to improve clinicians′ understanding of the characteristics of bronchiolitis during the COVID-19 epidemic.Methods:This was a multicenter clinical study, and the data have been collected from 23 children′s medical centers in China.All the clinical data were retrospectively collected from children with bronchiolitis who were hospitalized at each study center from January 1, 2019 to December 31, 2021.The results included gender, age at hospitalization, length of stay, respiratory syncytial virus(RSV) test results, severity rating, ICU treatment, and the total number of children hospitalized with respiratory tract infection during the same period.The clinical data of children with bronchiolitis in 2019 before COVID-19 epidemic and in 2020、2021 during COVID-19 epidemic were statistically analyzed and compared.Results:According to a summary of data provided by 23 children′s medical centers, there were 4 909 cases of bronchiolitis in 2019, 2 654 cases in 2020, and 3 500 cases in 2021.Compared with 2019, the number of bronchiolitis cases decreased by 45.94% in 2020 and 28.70% in 2021.In 2019, 2020 and 2021, there were no significant differences in gender ratio, age, and duration of hospitalization.Compared with 2019, the ratio of bronchiolitis to the total number of hospitalizations for respiratory tract infection decreased significantly in 2020 and 2021( χ2=12.762, P<0.05; χ2=84.845, P<0.05).The proportion of moderate to severe bronchiolitis cases in both 2020 and 2021 was lower than that in 2019, and the difference was statistically significant ( χ2=4.054, P<0.05; χ2=8.109, P<0.05).There was no statistically significant difference in the proportion of bronchiolitis cases requiring ICU treatment between 2019, 2020, and 2021 ( χ2=1.914, P>0.05).In 2019, a total of 52.60%(2 582/4 909) of children with bronchiolitis underwent RSV pathogen testing, and among them, there were 708 cases with RSV positive, accounting for 28.00%.In 2020, 54.14%(1 437/2 654) of children with bronchiolitis underwent RSV pathogen testing, and there were 403 cases with RSV positive, accounting for 28.04%.In 2021, 66.80%(2 238/3 500) of children with bronchiolitis underwent RSV pathogen testing, and there were 935 cases with RSV positive, accounting for 41.78%.Compared with 2019 and 2020, the RSV positive rate in 2021 showed a significant increase( χ2=99.673, P<0.05; χ2=71.292, P<0.05). Conclusion:During the COVID-19 epidemic, the implementation of epidemic prevention and control measures reduced the hospitalization rate and severity of bronchiolitis, but did not reduce the positive rate of RSV detection.

OBJECTIVES: To investigate the relationship between the fatty acid-binding protein 4 (FABP4) and colorectal cancer (CRC). METHODS: Using an enzyme-linked immunosorbent assay (ELISA), we measured the expression of FABP4 in plasma of 50 patients who underwent surgery for CRC from October 2017 to May 2018 and 50 healthy controls. The content of the visceral fat area (VFA) as seen with abdominal computed tomography (CT) scanning was measured by ImageJ software. The expression levels of FABP4, E-cadherin, and Snail proteins in CRC and adjacent tissues were determined by immunohistochemistry. RESULTS: The mean concentration of plasma FABP4 of CRC patients was higher than that of the control group (22.46 vs. 9.82 ng/mL; CONCLUSIONS High LPA and VFA were risk factors for increased plasma FABP4 in CRC patients. FABP4 protein was highly expressed in CRC tissues and associated with TNM stage, differentiation, and lymph node metastasis of CRC. The level of FABP4 in CRC tissue was correlated with E-cadherin and Snail expression, suggesting that FABP4 may promote CRC progression related to epithelial-mesenchymal transition (EMT).

Objective To evaluate the safety and efficacy of transplantation of purified CD34 + cells (PCCs) in treatment of critical limb ischemia (CLI) caused by thromboangiitis obliterans (TAO).Methods From May 2009 to June 2015,34 TAO-induced-CLI cases underwent PCCs transplantation.None of these patients were eligible for surgical or endovascular revascularization.G-CSF was subcutaneously injected for 5 days before peripheral CD34 + cells were isolated,purified and intramuscularly injected in the limbs.Patients were regularly follow-up.Results Technical success was achieved in all cases.The mean number of transplanted cells was (7.5 ± 2.4) × 105/kg.The follow-up was accomplished in 32 cases,ranging from 6 to 79 months (mean 45 ±24 months),and two patients were lost.Wong-Baker FACES pain rating scale score significantly decreased from 8.0 ±2.0(4-10)to 2.2 ±3.1 (P ＜0.05) at 1 month.The Peak pain-free walking time improved from (4.0 ± 2.0) min to (13.5 ± 5.3) min (P ＜ 0.05) at 3 months and (19.0 ± 3.1) min (P ＜ 0.05) at 6 months.The ankle-brachial index increased from 0.42 ± 0.20 to 0.50 ± 0.10 (P ＜ 0.05) at 3 months and 0.52 ± 0.11 (P ＜ 0.05) at 6 months,respectively.Transcutaneous partial oxygen pressure rose from (25 ± 11) mmHg to (48 ± 11) mmHg(P ＜ 0.05) at 3 months and (58 ± 10) mmHg (P ＜ 0.001) at 6 months,respectively.Ulcers healed in 21 out of 22 patients at (5 ± 4) months.The overall amputation-free survival rate was 94.1％ at 6 months and 91.2％ at 48 months.No major adverse events were observed perioperatively or postoperatively.Conclusions Transplantation of PCCs could yield safe,satisfactory and durable treatment outcomes in patients with TAO-induced-CLI.

Objective To evaluate the bone repair capacity ofpolylactic acid-polyglycolic acid copolymer (PLGA)/collagen type Ⅰ (CoI) microspheres combined with BMSCs after being injected in intertrochanteric bone defect of osteoporotic female rats.Methods Prepared PLGA microspheres.The microspheres were coated with Col.BMSCs of the third passage were cultured with PLGA/CoI microspheres.Forty 3-month-old female SD rats were ovariectomized to establish osteoporotic animal models.The osteoporotic rats were randomly divided into 5 groups,including SHAM group,PBS group,Cell group,MS group and Cell+ MS group.There were 8 rats in each group.Different material was injected into the intertrochanteric bone defect site which was made with electric drill.Four rats of each group were sacrificed at 1 month and 3 months post-operation.The fenora were taken to measure the intertrochanteric bone mineral density (BMD) with DEXA and evaluate trabecular stucture with Micro CT.Results After 7 days of coculture,BMSCs seeded on PLGA/CoI microspheres had nice adherance and proliferation.There was no difference of BMC and BMD among all groups at 1 month post-operation.Tb.Th of Cell+MS group was higher than that of PBS group and MS group at 1 month post-operation.％Tb.Ar of Cell+MS group was higher than that of Cell group and MS group at 1 month post-operation.Tb.Sp of Cell+MS group had a tendence to decrease compared with other groups but there was no statistical difference at 1 month post-operation.After 3 months of operation,the BMC of Cell+MS group had a tendence to increase compared with that of PBS group and MS group but showed no statistical difference.BMD and Tb.Th of Cell+MS group was higher than those of other groups.％Tb.Ar of Cell+MS group was higher than that of SHAM group and PBS group.Tb.Sp of Cell+MS group had a tendence to reduce compared with other groups but showed no statistical difference.Conclusion The bone defect of osteoporotic site can be repaired 1 month after the injection of the PLGA/CoI microspheres combined with BMSCs.The trabecular reconstruction and bone quality of osteoporotic site can be improved 3 months after the injection.

Objective To investigate the role of hybrid bone grafting using autograft and freezedried allograft bone in restoration of acetabular bone defect,as well as to evaluate the clinical results of this grafting technique combined with acetabular scaffold in dealing with massive acetabular deficiency.Methods Between April 1999 to December 2007,18 patients (19 hips) underwent acetabular revision by using a mixture of autograft and allogenic freeze-dried cancellous bone particles plus acetabular scaffold.There were 8males and 10 females,aged from 33 to 76 years (average,64.7 years).The acetabular defects were caused by aseptic loosening of primary total hip arthroplasty in 17 patients and osteoarthritis secondary to osteotomy in 1 case of acetabular dysplasia.There were 5 cases of Paprosky Ⅱ B defect,2 Paprosky Ⅱ C defect,6 Paprosky ⅢA defect and 6 Paprosky ⅢB defect.Results All patients were followed up for 3.6 to 12.3 years (average,6.5 years).Harris hip score improved from preoperative 38.7±9.6 to 87.6±7.8 at final follow-up.According to X-rays,bone incorporation evidenced by trabecular bridging of the host-donor interface was found at 3to 6 months postoperatively,and effective bone incorporation was achieved in all cases one year postoperatively.Polyethylene wear occurred in one case.Acetabular component loosening was not found at final follow up.Conclusion Impacted bone grafting using a mixture of autograft and freeze-dried allograft bone can efficiently restore acetabular bone defect.Adding autograft bone to freeze-dried allograft bone is a highly effective way of achieving graft incorporation.Hybrid bone grafting technique with acetabulum scaffold is an attractive option for the treatment of extensive acetabular deficiency.

Objective To evaluate the results and complications of hip arthroplasty performed as a salvage procedure after the failed treatment of intertrochanteric hip fractures in elderly patients. Methods Between 2004 and 2009,10 patients were treated with hip arthroplasty after the failed treatment of intertrochanteric fracture.There were six females and four males,at mean age of 75.7 years ( range,68-84 years).The initial treatment of fractures included dynamic hip screw (DHS) fixation in three cases,dynamic condyle screw (DCS) fixation in one,proximal femur fixation with reconstruction interlocking nail in three and conservative treatment without internal fixation in three.The failed procedures included avascular necrosis in four cases,cephalic implant cutting in three,nonunion in two and malunion associated with osteoarthritis in one.Joint hip replacement was performed except for pre-operative infection.Harris score at follow-up was recorded and prosthesis position was evaluated by imaging. Results Six patients were treated with total hip arthroplasty with a cemented cup (three patients) and an uncemented cup ( three patients) and four with a bipolar hemiarthroplasty.A long-stem implant was used in 5 of the 10 hips.The average duration of follow-up was 4.6 years (2-7 years).The mean duration of surgery was 128 minutes and mean blood loss was 764 ml.The mean Harris hip score increased from 37 preoperatively to 85 postoperatively.The functional results were satisfactory.One 84-year-old patient with the implant intact died 2 years postoperatively from a brain hemorrhage. Conclusions Hip arthroplasty is an effective salvage procedure after the failed treatment of intertrochanteric fractures in elderly patient.Most patients have better pain relief and functional improvements in spite of technical difficulties than primary arthroplasty.In the meantime,attention should be paid to patients with poor bone quality,bone loss,or articular cartilage damage.

Objective To summarize the perioperative characters of femoral neck fractures in patients aged at over 80 years by analyzing the surgical treatment procedures. Methods A retrospective study was done on data of patients with femoral neck fractures treated surgically from June 2000 and June 2008. There were 25 males and 36 females, at average age of 83.4 years (80-94 years). Of all, there were 53 patients with fresh fractures including six with type Garden Ⅰ or Ⅱ fractures and 47 with type Garden Ⅲ or Ⅳ fractures, eight with old fractures ( all type Garden Ⅳ). Fifty-one patients (84%) were accompanied with preexisted internal medical or neurological diseases. Six patients with type Garden Ⅰ or Ⅱ fractures were treated with cannulated screw fixation (CSF). Among 55 patients with type Garden Ⅲ or Ⅳ fractures inclu-ding 47 fresh fractures and 8 old ones, 53 patients were treated by hip hemiarthroplasty (HHA) but the other two by cemented total hip arthroplasty (THA) because of preexisting hip osteoarthritis. Results The average operation duration and blood loss were 51 minutes and 50 ml in CSF group, 81 minutes and 180 ml in HHA group, 105 minutes and 350 ml in THA group. Fifteen patients (25%) had postoperative com-plications, mostly hypotension, cardiac insufficiency and atrial fibrillation, accounting for 12%. Postoperative hemoglobin was decreased by 11.9%, 17.1% and 18. 1% on average respectively in CSF group, HHA group and THA group, and postoperative albumin decreased by 10.8%, 18. 1% and 20.2% on average respectively in CSF group, HHA group and THA group. There were 17 patients (28%) with hemoglobin below 100 g/L and four (7%) with albumin below 30 g/L after operation. Conclusions The patients aged ≥80 years with femoral neck fractures are usually accompanied with preexisted internal medical or neurological diseases and have high risk in operation. Adequate preoperative preparation and active prevention and treatment of perioperative complications are important for successful operation and good postoperative results.

BACKGROUND: The main pathological change of intervertebral disc herniation is that nucleus pulposus protrudes from ruptured annulus fibrosus, thus we can hypothesize that it is possible to prevent disc herniation prior to its protrusion by coagulating it as a whole.OBJECTIVE: To observe the coagulation effects of intervertebral disc nucleus pulposus by alum solution.DESIGN, TIME AND SETTING: A randomized controlled animal experiment was performed between September 2002 and April 2003 at Department of Animal Experiment, Peking University First Hospital, Beijing China.MATERIALS: Twenty-six healthy adult hybrid dogs, 9 for in vitro experiment and 17 for in vivo experiment, weighing 16-21kg, with no restrictions on male and female, were obtained from Department of Animal Experiment, Peking University First Hospital, Beijing, China.METHODS: Twenty canine in vitro intervertebral discs obtained from 5 dogs were randomly divided into 4 groups, with 5 discs in each group, and were put into 2.5%, 5%, 10% alum solutions and 0.9% physiological saline, respectively. Effects of disc coagulation were observed after immersing for 1 day and 10 days, respectively. Another 16 in vitro intervertebral discs obtained from 4 dogs, composed of L2/3, L3/4, L4/5, L5/6, were also injected with the above 4 experimental solutions, 0.15ml, respectively. Sixty-eight in vivo intervertebral discs were obtained from 17 dogs and divided into 4 groups: blank control group, physiological saline group, 10% alum solution+one puncture point group, and 10% alum solution+two puncture points group, 17 discs in each group. Harvesting time: 3 days, 2 weeks, 1 month and 3 months postoperation.MAIN OUTCOME MEASURES: Effects of alum solutions on the coagulation of the intervertebral discs and related histological changes were observed and an alum solution of suitable concentration was preliminarily selected. General observation, light microscopic observation and scanning electron microscopic observation were made of the nucleus pulposuses.RESULTS: In the in vitro and in vivo experiments, it was found that physiological saline did not produce the effect of coagulation on the nucleus pulposus, while immersion in the alum solution induced nucleus pulposus coagulation in the in vitro intervertebral discs. Also, as the concentration of the alum solution increased, the volume of the coagulated nucleus pulposus gradually decreased. After alum solution was injected into the in vitro intervertebral discs, no nucleus pulposus coagulation appeared. When the 10% alum solution was injected into the in vivo intervertebral discs, nucleus pulposus coagulation occurred, with the strongest coagulation effect reached at 1 month postoperation. This was manifested in the agglutination reaction centered around the puncture point. When there were 2 puncture points, 2 coagulated lumps might appear. There was an increase in the mesenchymal component of the coagulated nucleus pulposus. Histochemical and scanning electron microscopic examinations confirmed the proliferation of large numbers of collagen fibers in the mesenchyme.CONCLUSION: Alum can promote nucleus pulposus to coagulate around the injection point. This may be related to the increase of collagens and the fibrosis resulting from stimulation of the nucleus pulposus by alum solution.

Objective To evaluate the application of SOLIS in the surgery on anterior intervertebral fusion for the treatment of traumatic cervical disc protrnsion. Methods 53 traumatic single segment cervical disc protrusion were divided into three groups randomly. The A group (SOLIS) :n=18, SOLIS filled with autocancellous bone were implanted between the cervical vertebrae. The B group(Syncage) :n =16, as the first group Syncage filled with auto-cancellous bone were implanted. The C group:n=19,anterior cervical decompression and fusion with bone autograft and internal fixation with ACPS. The operations of the surgery on anterior cervical decompression in three groups were the same. Recovery of nerve function was observed by JOA score and the fusion state, stability and changes of interver-tebra height of fusion segment were evaluated by X ray. Results The average duration of the follow-up was 16.5 months in 53 cases. Bony fusion could be found 3～9months after operation in all cases. In all A (SOLIS) group cases,the movement of the implanted $OLIS Cage were not found. The heights of the cervical intervertebral spaces and the physiological curvature were restored without loss in the duration of follow-up. The average JOA was(10.4±2.4) be-fore operation and(14.9±2.0)after operation. There was highly significant variation between the former and the latter (P<0.01). In the B (Syncage)group,5 cases had cage subsidence, therefore the height of intervertebra and the phys-iological curvature were lost. The average JOA was (10.6±2.5) before operation and (13.2±2.3) after operation.There was significant variation between the former and the latter(P<0.05). In the C group the third group, the move-ment of the fixed titanium plate were not found in the duration of follow-up in 18 cases. The titanium plate fixation was loose in 1 case. The average JOA was(10.5±2.4) bofore operation and(15.1±1.9) after operation. There was high-ly significant variation between the former and the latter(P<0.01). After operation,there was significant difference in the JOA score between the A group and the B group,between the C group and the B group(P<0.05) ,and there was no difference between the A group and the C group(P>0.05). Conclusion Treatment of single segment prolapse of the cervical intervertebral disc with SOLIS cage has some advantages such as higher fusion rate, higher recovery rate of nerve function and low rate of loss of intervertebra] height.